5 files changed, 69 insertions, 7 deletions

diff --git a/scene/main/node.cpp b/scene/main/node.cpp
index 0aaba5491a..0b3a193d18 100644
--- a/scene/main/node.cpp
+++ b/scene/main/node.cpp
@@ -1716,14 +1716,17 @@ void Node::get_groups(List<GroupInfo> *p_groups) const {
 	}
 }
 
-bool Node::has_persistent_groups() const {
+int Node::get_persistent_group_count() const {
+
+	int count = 0;
 
 	for (const Map<StringName, GroupData>::Element *E = data.grouped.front(); E; E = E->next()) {
-		if (E->get().persistent)
-			return true;
+		if (E->get().persistent) {
+			count += 1;
+		}
 	}
 
-	return false;
+	return count;
 }
 void Node::_print_tree_pretty(const String &prefix, const bool last) {
 
diff --git a/scene/main/node.h b/scene/main/node.h
index 982bfcd620..67b40f6dfc 100644
--- a/scene/main/node.h
+++ b/scene/main/node.h
@@ -300,7 +300,7 @@ public:
 	};
 
 	void get_groups(List<GroupInfo> *p_groups) const;
-	bool has_persistent_groups() const;
+	int get_persistent_group_count() const;
 
 	void move_child(Node *p_child, int p_pos);
 	void raise();
diff --git a/scene/register_scene_types.cpp b/scene/register_scene_types.cpp
index 6c858e9d9a..53bdb4145f 100644
--- a/scene/register_scene_types.cpp
+++ b/scene/register_scene_types.cpp
@@ -530,6 +530,7 @@ void register_scene_types() {
 	ClassDB::register_class<VisualShaderNodeSwitch>();
 	ClassDB::register_class<VisualShaderNodeFresnel>();
 	ClassDB::register_class<VisualShaderNodeExpression>();
+	ClassDB::register_class<VisualShaderNodeGlobalExpression>();
 	ClassDB::register_class<VisualShaderNodeIs>();
 	ClassDB::register_class<VisualShaderNodeCompare>();
 
diff --git a/scene/resources/visual_shader.cpp b/scene/resources/visual_shader.cpp
index f6424b1920..f7d7c2d1bc 100644
--- a/scene/resources/visual_shader.cpp
+++ b/scene/resources/visual_shader.cpp
@@ -1205,6 +1205,22 @@ void VisualShader::_update_shader() const {
 
 	static const char *func_name[TYPE_MAX] = { "vertex", "fragment", "light" };
 
+	String global_expressions;
+	for (int i = 0, index = 0; i < TYPE_MAX; i++) {
+		for (Map<int, Node>::Element *E = graph[i].nodes.front(); E; E = E->next()) {
+			Ref<VisualShaderNodeGlobalExpression> global_expression = Object::cast_to<VisualShaderNodeGlobalExpression>(E->get().node.ptr());
+			if (global_expression.is_valid()) {
+
+				String expr = "";
+				expr += "// " + global_expression->get_caption() + ":" + itos(index++) + "\n";
+				expr += global_expression->generate_global(get_mode(), Type(i), -1);
+				expr = expr.replace("\n", "\n\t");
+				expr += "\n";
+				global_expressions += expr;
+			}
+		}
+	}
+
 	for (int i = 0; i < TYPE_MAX; i++) {
 
 		//make it faster to go around through shader
@@ -1239,6 +1255,7 @@ void VisualShader::_update_shader() const {
 	global_code += "\n\n";
 	String final_code = global_code;
 	final_code += global_code_per_node;
+	final_code += global_expressions;
 	String tcode = code;
 	for (int i = 0; i < TYPE_MAX; i++) {
 		tcode = tcode.insert(insertion_pos[i], global_code_per_func[Type(i)]);
@@ -2337,6 +2354,14 @@ void VisualShaderNodeGroupBase::_apply_port_changes() {
 	}
 }
 
+void VisualShaderNodeGroupBase::set_editable(bool p_enabled) {
+	editable = p_enabled;
+}
+
+bool VisualShaderNodeGroupBase::is_editable() const {
+	return editable;
+}
+
 void VisualShaderNodeGroupBase::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("set_size", "size"), &VisualShaderNodeGroupBase::set_size);
@@ -2372,6 +2397,9 @@ void VisualShaderNodeGroupBase::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("set_control", "control", "index"), &VisualShaderNodeGroupBase::set_control);
 	ClassDB::bind_method(D_METHOD("get_control", "index"), &VisualShaderNodeGroupBase::get_control);
+
+	ClassDB::bind_method(D_METHOD("set_editable", "enabled"), &VisualShaderNodeGroupBase::set_editable);
+	ClassDB::bind_method(D_METHOD("is_editable"), &VisualShaderNodeGroupBase::is_editable);
 }
 
 String VisualShaderNodeGroupBase::generate_code(Shader::Mode p_mode, VisualShader::Type p_type, int p_id, const String *p_input_vars, const String *p_output_vars, bool p_for_preview) const {
@@ -2382,6 +2410,7 @@ VisualShaderNodeGroupBase::VisualShaderNodeGroupBase() {
 	size = Size2(0, 0);
 	inputs = "";
 	outputs = "";
+	editable = false;
 }
 
 ////////////// Expression
@@ -2508,4 +2537,19 @@ void VisualShaderNodeExpression::_bind_methods() {
 
 VisualShaderNodeExpression::VisualShaderNodeExpression() {
 	expression = "";
+	set_editable(true);
+}
+
+////////////// Global Expression
+
+String VisualShaderNodeGlobalExpression::get_caption() const {
+	return "GlobalExpression";
+}
+
+String VisualShaderNodeGlobalExpression::generate_global(Shader::Mode p_mode, VisualShader::Type p_type, int p_id) const {
+	return expression;
+}
+
+VisualShaderNodeGlobalExpression::VisualShaderNodeGlobalExpression() {
+	set_editable(false);
 }
diff --git a/scene/resources/visual_shader.h b/scene/resources/visual_shader.h
index 951bd6f668..45beb8e6ca 100644
--- a/scene/resources/visual_shader.h
+++ b/scene/resources/visual_shader.h
@@ -372,6 +372,7 @@ protected:
 	Vector2 size;
 	String inputs;
 	String outputs;
+	bool editable;
 
 	struct Port {
 		PortType type;
@@ -427,6 +428,9 @@ public:
 	void set_control(Control *p_control, int p_index);
 	Control *get_control(int p_index);
 
+	void set_editable(bool p_enabled);
+	bool is_editable() const;
+
 	virtual String generate_code(Shader::Mode p_mode, VisualShader::Type p_type, int p_id, const String *p_input_vars, const String *p_output_vars, bool p_for_preview = false) const;
 
 	VisualShaderNodeGroupBase();
@@ -435,10 +439,9 @@ public:
 class VisualShaderNodeExpression : public VisualShaderNodeGroupBase {
 	GDCLASS(VisualShaderNodeExpression, VisualShaderNodeGroupBase);
 
-private:
+protected:
 	String expression;
 
-protected:
 	static void _bind_methods();
 
 public:
@@ -454,4 +457,15 @@ public:
 	VisualShaderNodeExpression();
 };
 
+class VisualShaderNodeGlobalExpression : public VisualShaderNodeExpression {
+	GDCLASS(VisualShaderNodeGlobalExpression, VisualShaderNodeExpression);
+
+public:
+	virtual String get_caption() const;
+
+	virtual String generate_global(Shader::Mode p_mode, VisualShader::Type p_type, int p_id) const;
+
+	VisualShaderNodeGlobalExpression();
+};
+
 #endif // VISUAL_SHADER_H